For example, as a medium processing device for reading or writing of medium information from or in a medium in which information is recorded, a card reader has been known in which medium information in a card-shaped medium provided with an information recording part (information recording means) such as a magnetic stripe or an IC chip is read from or written in the card-shaped medium. The card reader is generally mounted on an apparatus or an equipment such as an ATM device (automated teller machine) or a CD machine (cash dispenser).
In recent years, the number of crimes that a third person other than an owner of a card-shaped medium steals the card-shaped medium has been rapidly increased. The third person reads personal identification information recorded in the stolen card-shaped medium to use illegally for performing personal identification or the third person forges a card-shaped medium or the like to illegally use the medium, which has become a major social problem.
Conventionally, a card reader (hereinafter, referred to as a prior art 1) has been proposed which is provided with a card locking device having a pull-out prevention lock mechanism for preventing illegal use of a card-shaped medium by a criminal (see, for example, Patent Literature 1).
In the prior art 1, even when a criminal hinders ejection of a card-shaped medium by a trick which is secretly attached to a card reader and, even when the criminal tries to pull out the card-shaped medium while a user has been left, the pull-out prevention lock mechanism is operated so that a lock tooth bites into the card-shaped medium to lock the card-shaped medium at the position. In this manner, since the card-shaped medium located in the inside of the card reader is locked so as not to be moved, the card-shaped medium is prevented from being illegally pulled out by a criminal. As a result, an illegal use of a card-shaped medium by a criminal is prevented from occurring in advance.